Monitoring Monitors: a Biological Perspective on the Commercial

Monitoring Monitors: A Biological Perspectiveon the CommercialHarvesting of IndonesianReptiles

R. SHTNE,P. HaRLow. AMEARTY^Nro,BoEADr. MuMfuNr & J. S. KEocH

AlLhougha few speciesof lndoneslansnrkes and lizardssuppon large scale haivesrs for both intcrDationaland domcsric !sc. thc basicbiobgy aDdnatuel historyof the harvested lrxa remainpoody knowr. We obrxinedexteNive nrformaiior on lheselopics by neasurlng and disscctingspccnncns of fbu spccics(,,1.ro./'old!i jdrani.us, Prttnn .wr6, P. [email protected] vatanus sulvar)/) collecledand killed for lhe comnercialleather indnshy. Our dataon greaterthan 2.000specimeN corslitute the first quandtatlveinformatlon o! thc sizes,scxcs ard rclroductiycstatus of thc harvcstcdanimals, as wcll asp.oliding bas'c drta on Lhelood habiLsand reptudu.tive bntogy ol thesegianL rropical species. we discnss the implicationsof ou fesullsfor the long rem Nsrainabilityof lhc comnicfcialhaNcst, andconnncnt on issucsrelevant to the nranagementof LteseinporLant nalural resour.es.

MEMANTAU BIAWAK: SATU PANDANGANBIOLOGI TERHADAP PENANGKA- PAN KOMERSIAI, BANGSA REPTIL INDONESIA Meskipunbeberapa spesies ular dan biawakdi hdonesiaditargkap d.l.rn jumlah Lrcsal untukpengeunarn di daiamdan luif negcri,biologi d!s!r dansc.jarah llani dari laksdyug diLangkapittr rnasihbelufr banyakdikeLahui. Kani Lelahnendapalkan baoyrk informrsi niengenaitopik ini nielaluipeneukuraD dan pembedalnn terhada! cmpat spcsics (,{./o.roldes jawnicus, P\thon cuttus,P. /eti.ulatts. d$ varunussat atar) yang biasanyadnangkap da. dibunuhnntuk lndustri kulit. Datakami mengenailebih da.l2.000 spesimen merupakan infomasi kuantltltif Dc|tam! unluk uluratr, jc.is kcla'nin, dan sLatL$reprodukti!itas hesanhewan yang dlangkapnu. Sehnt itu datak.mi jLrgamembelikatr infonasi dasaf Den8enaikebiaslan makan dan biologi fcp.oduksidld spcsicsspcsies tropis ydng besar itu. Makal,rhini membahasinplikasi dari hasil penyelidikarkami lerhad.pkeberlanjuta! janeka panjangpenangkap.n kortr.Nial. serta mcneulasisu isu yang rclevan dengan Danajcmcnsutnbcrdaya alan yang pcnlingtc.scbu1.

Obwohl nur welige der S.hlangen-md EchsenarLenlndonesiens in gro6enMaBsrab nation.lund internationalgehandelt werden, sind weder die Grudlagen der BiologicDoch dcf Lcbcnsgcwohnhcitcndiescr Afien bekannl.wir hdbenumlingreiche lnlornationen hie.zurnha.d von Mesungenund Unre^nchungena. vier AJle[ die fij| denLedcfhandol bcsondcrswichtig sind, zusammcngctragcD. Eshandclt sich dabei um A.ro.nordurjar",ni&s, Plthon drtus. P. tztit:tlantrmd vald,lr saldtil. UnsereDaten, die m iiber 2000Tieen erhoberwurde[ liefernersmals quantitat]veInfornailonen iiber GfdBc,Gcscl cchl und Rcproduktionsslalusdicscr A|tcn. Dadbcr hinauswurden das Nahrung$spektrum und die Fonp0anzungsbiologiedieser dorchwegs groBwiichsigen topischen Repiilien.rten .naly siert. Die Bedeutun8unserer Ergebnise liir einc langliistig nlclhaltigc konmerzielle NutTungdieser Aften und die Aspekle,die liir dasManagenent dieser wichligen natnrli chen Ressourcenrelevarl sird. werder diskutietl.

CoDscrralion.Tradc.trd Suna,mblc Ur. orI-i7a'dsard Snak.r in I' o 1993Deutclie Ceselkchrltfiir Ile,petol.sieu.dTeruieDkunde (DGHT) 6l R. SHNE,P. H^Rr-ow.AMBARIyANTo. BoEADr, MurrrrNr & J.S. K'rocn

INTRODUCTION The repriljan fauna of Indonesia is remarkable fof its cxtaordinnry diversit-vas well as fof thc spectacuhr nature of many of thc comPonent species. Severrt Irrdoncsi.tDrcplile species attain very largc body sizes, lbr example, Indonesi.r posscsscsboth the world's largest lizrrd (vd.dtrrs konkdoensis) nnd the world's longcsl snake \Prthon rdiculatus). This large body size. togethcr with the abundance ol several such taxr, hrs neant ihat these aninrals constitule a signilicanl resourcefor hdonesinn pcoplc. Thrs, many of the lafger spccics have been harvestedfor domestic uscs for r very long linle. More fcccntly, hrge-scale commercial harvestinghas flourished, wilh a primdry focus on thc skins of snakes : and lizafds for usc in thc intcrnational luxury leather hadc. Even more recently. a growing dcmand for reptile meal and for medicinrlly vrluable body pafis (such as the gall bhdder) has stimulated a gro$,ing m.trket in the expof of live reptilcs ior num.tn consunpron. Dcspite this irtensive exploitrtion. rcmarknbly little is lnown abouLthc basic biology ofthe reptile speciesthat arc bcing harvested.Our ignorancein tlris respect docs not reflect any specific att butc of lndonesian reptilesr inxtcad, i1 simply reflects the general s.nrcity of intbnnaiion aboul lhe biology of rny tropical reptiles anywhere in thc world or indeed.the biology of.tny rcplile speciesother than those occuriDg in cold-temperatehabitats iD Europc and Nofh America (..8. Stsi.rH.1993, SrrrNE& MADSEN1996). Ihis ignorance stimulated the study that forns the basis ot' the preseDtreporl. Allhough our original intention wrs simply to docunent lhe basic biology of gianL tropical repnles. it soon bccamc apparent rhat the debate on long ternr sustainrbilily of the lndonesian rcltilc haNest wis being carried on in the absenccof rcliable ecological infonnation. Hcncc, rve have attemptedto b.ing our data 1()bcar on some of the relevant issucs. ln this paper. we will rcvielv sone of the n.tin findings ol our studiesto date. with patlicular emphxsis on lhe prospects for long tern sustainability of the commercial tradc. Allhough our study is still in progrcss. some parts have been comtlctcd and have already appearedir thc pimary scientitic literature (SHTNEet al. 1995, 1996). Other parls of thc work hrve been submitted for publication- In order to reduce duplication. wc will reslrict the cu ent paper to a broad ove 'iew of the relevart results, and locus on their implications for sust.rnrabilityof the

MATERIALS AND METHODS The logistical problems associalcd with the ecological study of large secretive reptiles. especially snrkes, hrve atkacted considcrrblc scienlific altention k.8. TLRNFR1977). Thc overwhelming conclusion of pracliLionersin this field is that population ccology studies are likely to bc fc.rsible lbr only a small proportion ol $nakc spccies mostly. small arimals that inhabit relatively opeD habit{ts. occur in high dcnsities,and are relatively easy to iil]d and cnpture.EveD the nrosl r'dent .tdvocaLcsof field studieson snakeecology (e.s- SEICEL1993) would conccde that it is virtually impossible to obtrin rclirble irtbrnation on popul:rtion dcnsities of large snakesinhabiting complcx lropical habitats, at le.Nt on a spatial scale large enough to permit generalizing 1(] broader areas.The problcms are several. First. most pythons rrc wcll carnoxflaged ambush prednlors. Iling in wait fbr passing prey itcms. The snakes are hence innubilc for long peiods. and are lirtually

62 BioloSicalPc$pcctive on the ConnncrcixlHarvesting of RePLiles impossiblc 1o lind al these timcs. Second, the lropical clinrate re'noves any need tbr ihe snakesto bask lo ..risc thek body tempcrntures.so that another common reason for snakes to movc about (and thus, become availablc fbr captufe) is renovcd (d.g. SFi\u & MADSEN1996). Thid, the population densilies ofsuch large anin1xlsare ljkely to be relatively low, and the distribution of annnals anrong larious habita! lypcs is likely to v.try strongly among seasons(e 8. Sr.rP& SUINE 1988.MADS & SIINE, 1995).]]ou h, the animal$ nrc polentially capablcol long- distancemovemcnts, so that it will bc difticult orimpossible to separateinnnigmtion and en gration frorn recruitment iDd mortality This is not to sav that field studies on the Indolcsian reptiles arc impossible: simply that thc appropriatelcchniqres (such as rxdiolelemetry) will bc lhose that providc insighls irto gencral ecology. behalior, movement pattcrns and habitat usc, ther thar popul,tLiondemoSraphy. In view of the rlmosl insurmountrblc obslrcles to demogrxphicwork on ffec mnging snakes.wc.rdopted a sitnpler and morc direct appro.tch.The large numbcrs of specinens collected and killsd for the conmercial trade, and the fact t|at mxny of these animtls rre brought alivc to the skinning factories, provide an opportunlty for relearchers to gathe. dcLailed information on thcse anirnals imnredialely after they .trc killed. Thjs kind of sludv is not a $bsLiLutelbr detailed ficld research.bu! it provides a cos! cficclive and time-effectivc techniquefor amassinga large quantity ot' infbrm.ttior on inportant biologicrl arributes ofthc harvestedtaxa.Cleafly, infbrnlation oD thc characterjstics (sexcs. sizes. etc.) of the harvested aninrrls is slso dircctly relevant to rDy cvlluation of lhe suslrinability of thc industry. Hence. we cnrricd out a serjesof aips io two areasin Sumatraro ex,itnine the carcassesof freshly killed reptiies al skinning factorics The first threc lrips were 1(rPalembang in southern Sumatra.and the lbuth lrip \\'rs to ihe Medan area in northern Sumalra. On 3ll tbuf lrips, large numbe* of specimenswcre exannned (Tab. l). Our procedureswe.e vcry straightfbrward We weighed .nd neasured the reptile .ts soon as it was killcd (or imnedinlcly befbrehand).and then dissectedi1 after it was skinned. Our measurementsincluded head lengih. snout-vent length, :Ind iail lergth. Wc scored sex and rcproduciive statusby visual inspection ol the gonads.and removcd all prey items in the alinentary trlcl for later identilication. In the case of manmalian prey, wc sectionedfur sxmples and idenlificd lhem bv conparison wiLh a referencecollcclion from specirncnsat the Bogor Mnseum

I'alcnbang alea Mcdrn area (3 rrips) (1 irip) Actuchotdusjaranicus 101 (Ulai brot. karung,fileslake) 35 511 (Sancapadi, gerdan-s, blood pylhon) tlthon rencutatus t JJ6J l9 (Sancabatik, sawah,reticulatcd python) t66 125 (Bixwak, water moDilor)

Tab. lt samplcsires of reptilescxamined rr skinnlngPremises in Sunalraover theperiod July 1993Io September1996.

R. SHTNE,P. HARLow, ANrBARry^Nro,BoEADr, MUMFUNT& J.S. KEocH

RESUI,TS Table 2 providcs a broad overview of relevanr resulls from our wott to dalc. The foufharvcsted spcciestha! we exanined di trin,"uny t,oirr, t .t ,orn" ."nri"t",rt tends werc also cvidenr. (i) Se&aL dimo.philltr iI bqdJ lizE Fcnrales.grow nuch larger rhan nrl,atesin Aoochoftlus jaranicus and ptthan teticuLatus, p_ bt not in curtus. Mite Vamnus sallarar grow targer tiran feiales. rlrhou;h Iner\ d,.f.,encr Jpfe: rt ru be .,n!trer,,,,r,,.,i .". ,r,.',"," nlr,,i "in,., \arr1.J. Thi. Inaj he due ru co .\'or\ di.rJrd.ni rtret;rBc.r mJtc, (s r\i er dl 1996). (ii) Ser !q!e! aI h.tNeslcd speqlmens Relatively equal numbers of nnlcs and felnales are rakcn in most of the bxrvested species(Tab. 2). The ninnnunr sizes of anin.tls colccted is sin lar for ,he qirhin $.u \e\.\ eich ut In, .pecrc..Hou,.\er m"r1 or rne ri.n.te..ri.. tulc,!rein n.t5.shcreiri.rt no't attot th. mdtesrrerol|tr.. thi.hir.rrjtecr.rhe lacrlhat nnlcs aftain mainrily ar sm4ller sizesihan fenales ir all ofthe specieswc studicd (e!cn h rhc vaftnids. where males uttinrately attain r",g". r],.i ir,", fenmlcs). wirh the result rhat rnosl of tire collecred In;u, "* ,a,ji ",,irn,,rruiii mJn) ^i,he r.mJle'hJ\e .,' ro ir.,,n m:r.rrrir). (iii) Reploductive altpu Reproduction jn is highty sc.rsoml atl of the sndke species studied. but conriru(. f,{ Ino,ru rhi Je in rhe!: r.,nrdtrl,,rd. .t r.h ;nJ t, er 5ue, \x \ rfonJriv.' geolJbo tt),p\rhnn ttttustncj ta,.tnu,,nr,r,"r) ro,,n ",.,"s:. oran r'.\utr|thott4ti.dl,tth,xndA,.torh,,rdh\jo,rr,,r.t Ho"",.r.,tr,.t,rri, vJry cun.;dihbly e\ cn s rrhinrhe ,ame ,prcie,. n,^.rt) rlen.ndino .n rheh^J) 5r/, oI Inc ,ernaii. Lrrgc rer,cr'trredp)rhun. crn pro,lu,e up r,, tUu ..sx. rn , sLnslc rlulLh. lr bolh rericul,,rcdp)l\on, inJ titeslale5.aJLrtl tim",e. c" n.r rep,,,Ou-.e every year alicr aftaining marudry, as is indicated by the f.actrhar a consi.lerabie tropofl,on ol aJul, Icnute5 "'e ronrctrrodu.U\e\\hen rhr) ,re co,tecr.J. In i"nlrrn. iPrlale .o1,o'", va,at'11 cin trodu(. Jt te.rr hfee ..,urch.f,$itt.in ! (iv) load luut! .Te.re.,lif,er .Th.ha^rnea con,rdcrrht)InJieraq trbrr,. I.rte:nbte. ear rjsne,.$n(.c} vdr,,rrrjse, nr!n) irvenebrJte5r. se r, \e ebrJre. p)rhon. r!l

P. r.ti.uktrs \t. saLtutor Sexualsize dimorphisn lemale larger Fmate=malc lenralc largd nalc hrg{ ser rario oi c.rre,r.. sDaimeN {7e malc) 31% 41.h 52q. ,q. q" .i.O"rt .tp"rin"* ,a,7 i -.i". S+* i,, .""t., S.tC.i" .,1* 93./, i; .-t* !!& i!!l!!lel-' SE t!!4ales 217, nr feddes 55./o-" in fc,nares A\.ns<,i,'.hot!,; _". ,";;,,,'";j l,;"- i,r] "r -,., r.."r". r{roductile in any le.r 64q. unknoqn 389, Ioo.n frrJ \"o1. ri.he. hanmars Ptusvertebrares Tab. 2. A sunmary of ecol.Jgic.lrraits of rndonesianrcplile slecies use.l rbr ihe commercial lcatherindustry. See rext for mcftods.ard origin;l prp;rs for ftrlt derrils.

64 BiologicalPe6pectile on rhe Connercial HarvesLingor Repriles nroslly narnmals, wiLlr rals being thc mdor food sourcc lbr smallu snlkes rirclLLling\iflrdll) :rll P,rr,r, ,,,r^ 1. Ldrge reticulntedpythons take a very diverse diet, including large mammals such as monkeys.pangolins, porcupines, nouse-deer and wild piss.

DISCUSSION What can ihese data |ell us about the long-rerm sustainabiliryof the connnercial and domestic harvestof Indonesianrepliles? The issue is an enormousll, complex one. and involves a whole series of culiural, political and ecoronic tactors in addition to the straightforward biological questions.lr ar attempt to addressthe l'lologlcal conrponent of this issue, it may be useful to consider n variety of rttributcs that cnhancc a spccies' ability to withsiand high rrlcs of ofitakc (i.c. additional sourcesof mortrliry dre lo hrman activities)- (i) Geoelaplie distrlbrlion Clearly, speciesthat occur over very large geographicareas are less vulnerable to extinclion regardless of the endangering process than species that are resricred to smaller arens. All tbur of the species we siudied are very widely distributed acrossAsia. (ii) Popdatio! conthuiti, Speciestha! occur as a seriesof relatively discfete populations (as in the case of isl.tnd taxa, or fornrs thrt are restricted to habitrt 'isluds' by ecokrgical specinlization) are norc vulnerable lo local cxtinction, and the probabilily of iecolonisation of suitable habitat pockets after such local exlinction is greally reduced. The lndonesiin harvestedreptile speciestend to be habiiat generalisrs, and are highly vagile. Althoxgh rve lack detailed intbrmation on movemeni patterns.it seemslikeiy that individuals of all of these laxa would be capable of long-distancedispersal. For exanple, water monitors arrived as some of the first coloDizeruof Krakatauafter rhe island's fanous volcanic erupiion (SrNr(rN& lisKe r983). (iii) N.s!=h4rr!1sdsrs4! The incredible complexity and spatial hcterogeneityof Indonesianhabirats and societies (econonies, religions, social systems) mean that collecdng ellb is highly heterogeneous.ln many areasparticular speciesare not comnlon enoxgh to warranl commercial collection. or the costs of transport to markeis are too great. ln other areas(c.9. nofthern Sumatla). traditional custons preclude harvesting of these aninals. Thus. colnnlercial haNesting does not occur unifofmly over ihe

(iv) Explqrta!&! af disturbed tabrt4!! Human activiLics (nolxbly,.tg.iculLurc and urbanizalion) havc subslantiaily lranslbrmed large areas of Indonesia. In Inmny cases, lhe end result of ihese activities has been to provide a vaslly increased supply of potential prey items (especially rodents. in ihe case of ihe two harvestedpython species).The ability of rhe hanested taxa ro persist even in highly disturbed habiiats. and rake advaniageofanthroposenically-derived fbod sources,is probably a major conirlbutor to the continuedabundance ofthese reptilesin lndonesia.This ecologicalflexibil ity also meansthat extirpatior of the haNested taxa is extremely unlikely. Indeed. in some areasthe reptiles may be more comlnon row than they were prior to human intervenlion. In particular, it seems likely that the construction of pitlm oil planlations has subslantially incrcascd population dcnsities of Plt'r.r? .!,trs. R. SHjN!.P. H^RLow,AMts^RryAN1o. BoEADr. MurrpuNl & J.S.KroaH

(v) Rcprad!!1i !e ratgs It is gcnerallylrue that laryebodicd lpecies rcpfoduceat tower rates rhan small-bodicdspecies, and henceare less weit,suircdio suslajnjnghigh faresof mort! rty. Thc lower rcproducrilcmte of targerspecic! typicalty reflacrsborh a delayin malurationand a reducrionin reproductjvetrcquency rclative to sraller taxr (PHrERs1983. RErss 1989). presumabty, thc generatiiyofihis cffed mny have contributedto ilrLcrnationalconservarion conccrns abour fie long-lcrnrviabitjty of the cnmmercialrfade in giant tndoncsiarreprjtcs. Horvcver. this vierv is overty simplistic.becatrse it doesnot rake into accountthe ext.aordinaryftexibitirl oi life-historytraits in reprilcsi especirlll, the ovcrwhetning inr,rrrcacesof iood supplyaDd tempc.rture (e.8. M^DSEN & SHNE1993). onr trehninxry anilyscs, combinedwith exiensiveinfbnnation on cxptivepylhons and vrrinids. ;uggesithai thcsetaxa arc actuallyfast,growing and carly maturnrg(Ross & MARti 1990. BARKTR& BARKTRi994). Hence.they are rclaiively ;et1 suiled to comncrci?l exploiLation;thc low reproductiveilcquencies of femnlcreticulard pythons(Tab. 2) would seem10 ofter thc onty caurjonarylatc in this nspect. (!i) Colleclingtechniq!!e! Thc wayin whi.h feprilcsarecollccred atso has jmplicatuns for thcsustainabitity of lhe hrrvest.Techniques which porenriallycollccr all ol Lheanirnats in an arc,r, or damagcthe habitatin thc courseof collectingspecimens (..g. poilo ng or bombing coral reels) have rbc potentiat to seiously depicle poputalbns. In contfast.techniques which rely on theanimlt's activity(such thar x high proporrion of thc populalionis essenriallyinvutnerable for nuch of lhe rillre) ,". i""i r;t.ty to causelong-tcrm consenntion probtelns. In rhecase of the tndoncsianreptitei. nlostcollecting sccms io bc focusedon acti.\,etymoving rninlats. Rrdiorete;cLric studieso'r otherpythonid. v.tranid and acrochordjd specics suggesl rhat these nay .ui',rir,rr.ull)dsmrll prop^ iunot rhc t,,putJlon : | !n) p^irr inrimf ,ps S r.\l & L.vB,r lo85\ &S,r\r tobb.s,\ & M,n,r. tqnr,t. Srmilarly. collectingeftbrts a.e more tikety ro bc susrainabteif a significanl-tur proportionof tfie animalsremo\,cd afe malcs.This sccmsto Uerhe case mosr of lhc ha|v-esredIndonesian species (Tab. 2). Civen rhemating syslens and high mobility of thescanimals, reno.\,at of nales js unlikel] to h;ve any significa'nt rong-temrrmpact on the viability of naturalpoputations. The cnd result of theseconsideration! is to snggesirha! rhe tbur Indonesian .eptile spcciesrhal we have studiedarc well-sniledto susLaininghigh levels of offtake.Thelr dre aii widely-disLiburedccotogicat generatists, cap;ble;f persisling disturbcdfiabitats and ablc ro take advantageof anificjrlty-enhancedfoo; supplies.Thus, it is diificuh ro bctieverhaL the cuncnt commcrciatand donestic harvestposes any conccivablethrcat ro the tong-termpersisrencc of theselaxa in lndoncsia.Therc can be no doubtlhit jntenseharvesti;g car subsrantiaityreduce local populations, jn ,tndmay cause locat cxrinctions fragnrcntedhabjlnts anombty. on small islands).However, extinction of thesetaxa over rheir enrne rangeis vidually uninagnrable. Althonghthis co.clusionsuggests lhrt hanesrjngis indecdsusrainabte. ir rells us liule aboutthe lcvels of sustainabteofftake. Ir;lso 'lusiainabitity, avoidsthe morc complex issueof the neaningof in this contexL.Different people discus;ing this issueoftcn seen 10 employdifferent definirions, aDd it ii worth exprorin! possibletypes of suslrinability in nore dcrail. Onc could imagine rhrt rh; lndoncsiarreprilc harreslnighr fnil k) be susirinabte(i.c_ be unabieto conln e long-term)for sevc.aldiftercn! reasons:

66 Blological PeApeclivc on the Conmcrcial Hxrvestine of RePLiles

(;) Extinction Gilbsr: glqbql ar bqu: U the spccjcs ceasesto cxrsl n an area. lhc trade must obliously ceasc. This situatioD is highly improbable tor thc Indonesian harvcsled taxa, nt lcrsl on ihe largcr islards (ii) Ecological a!{Uar ccononic dismplb!: Removal of large prcdalors (especiallypylhons) might cnable a significanr increasein prcy abundanccsln the case of rlinrs (the prinrry prey for snall ?. fdrl.&la.es, and all sizc clrsses of P. .r,rl,r), such an incrcasecould halc significant implications economicrllv (in terms of bss of agricultural productioD).rs $'ell as in lcrms of disrupt;on to naxrral eco$ystcmtunction. This possibility is difficuit to evaluatc,but it leems 1ikelv lhat rodcnl reproductive rales are so high thrt predation by ectothernrsis unlikelv !o excrl signiticant conrrol (t.g. M^DsrN & SHNE.unpubl. data). Furthcr invesngation oi lhis possihility would be of great value (iii) Connnercialfeasibilir!: Once populrtion densitiesafc reducedto vcfv low levels. infraslructural cosLs may rendcr continued harvesting of lpccimens economic.tlly unfeasiblc. Presumably. domeslic consnmption would continue undef lhcse circumstanccs,but at a reduccdintensity This scenarioi! r likclv one' parijcularly in areaswhcrc hrnan activitics reduce usablc habitatsfor thc rcpliles For cxanlple, the.urcnlly low levcls of ofTtake of ijliculated pythons in Javn presunably reflect thc nassive deforcslation and habilal alteration over nuch of this islind.

RECOMMENDATIONS fOR FUTURT] WORK The harvest of Indonesianreptilcs confers significant econonic benefit! t') nranv people, and our prelimirary ccological data on lhe exploited speciessuggcst that such a ha|vcsl hns the poteDtialto be sustainablein lhe long term Nonethclcss,n is very difficxlt to establishexactly wh.t1 lc\el of offtakc oifers the mott cfficient conservation saategy. In order to addrcss lhis issue. wc rccommend two things: furrhcr researchand rcgnlar monito'jng. (i) Research.Additional data froln the stinning fhctories will be needed to csiablish biologicai attributes oi lhe speciesbcing harvesied,rnd partjculrrly ro quantify the dcg€e and naturc of spatial and tcnporal heterogcneitvin i'nporlant ecological trails. For exanrple, a compa.ison of python and varanid lopularions liom Kalimantan feffar Sunatra would bc very instNcLivc we also nccd more information on ihe genetic distnrctivenessol local (especiallv,island) populrtions. and tlre dctailed natunl history (movcment pattems, habilat u!e. clc-) of dre

(ii) Llgliloling. The natxre of thc commercitrltrrde (large runbcrs of animals hrorght in alive io central destinat;onsfbr killing and skinning) makes the svstc'n ideally suited to nonitoring. Additionally. the cooperationof thc relevant mduslry (vialRAl A andACSUG)and lhe sinplioity rnd cost-effectivcnessof the techniques, means thar it should be fcasible to mon;tor the anim{ls that are broughl in tbr skinning. If this procedurcproves diffjcull to implement, a simple recording of the numbers and sizes of skins of each specicscollected in a given area ovcr a known timespr! would be an evcn nore straiglrlforward approach lf lndonesian wildlite autho ties initiated slrveys at appropriatesites in Sumatra and Krlimnntan. thev would be able !o oblrin extensive and reliable santpling of the lrade With such drla over several years, any subslantial decreascin the wild populalions sfiould then be appafentirom shifis in the body sizes,tDd numbers of collected specnnens R. SHINE,P. H^RLow. ANiBARTy^Nro,Bor^Dr, Mu\4ruNr& J.S. KEo.rH

ACKNOWLEDGMENTS Wc thank thc nany pcople who have contribrred to rhe successof ouf tndonesian studres. w_e ladicLrlarly thank the rcpresenrarivesof IRATA, cspecialy Mr. sApu,RA.Mr. HAS^N,M.. AuAN RuswAN.Mr. SuDrnv,u and Mr. Suxoso anrl rhcir sraff, for allowing us ticc accessto their prcmises to cxamine reptiles_pefmirs for the work were given by LIPI and PHt A.

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AuthoA: R. SHTNE.P HARLowaDd J.S. Kf.oc!, Univosity of Sydney.School of Biolosical sciences.Building AO8. N.S.w. 2006. Australia; ,lvurrynLo. FpK_Universir; -o. ( of DiponeJ, Terh"lJne dr"fu..s/mdran8.InJurc... Bor\Lr ,nd M !q \, R!.;x(h (.nI. anr Dc\ernfmor lo Bjuos) |Pt. Jt. I H. t-xnudNo ,It.8o8or tr.t,2.